C++ Syntax Details

Item
Description
Example
  syntax Think of this as a combination of spelling and punctuation. C++ only understands you if you use perfect "grammar.". C++ will not work if you don't use the right spelling or use the wrong punctuation.
  case sensitive C++ is case sensitive. That means a command typed as COUT or Cout will not work; the proper syntax is cout
// Comment

//This is a comment.

/* This is also a comment.
It is a multi-line comment.
Notice how it starts and stops.*/

Comments let you leave notes to yourself and others. You should use *lots* of comments in your programs.
#include <iostream> preprocessor directive This sends a message to the compiler to include other items with your program. In this case, it tells C++ to allow you to use basic input and output utility programs. This is an instruction to the compiler to include a header file, as opposed to the rest of your code that compiles.
using namespace std; the using directive A C++ program can be divided into different namespaces. We'll always use the namespace std, which saves us work later (we don't have to enter std::cout every time we want to use the cout statement.

int main()
{
// put commands here
return 0;
}

 

 The main function Every program has a main function. It must include all of the elements shown.
{} curly brackets Curly brackets are used to "block" the codes in each function.
cout << "message"; standard output

Using the built-in cout command, you can make messages print to the console (screen). Notice that the message is enclosed in quotes, and the entire statement ends with a ;

The << is called the insertion operator. You are telling C++ to insert data into an output stream (send it to the screen).

You can put several << on the same line.
cout << "here's some stuff" << variable << "here's some more stuff";

 
endl new line

Go to a new line. Use with the cout statement:

cout << "Hello, mommy!" << endl;
\n new line

Adds a new line, also. Put inside your "output" statement:

cout << "\n\n\n This goes down three lines!!";